As for the noises, have you checked to see if the big gland nut that holds the shock insert into the strut tube is tight? Sometimes those will loosen up and make bad noises as the shock jumps up and down inside the tube...

The gland nut? `Bingo!` Today afternoon. Car`s lifted. Shock insert does have substantial play inside the tube. Nut looks *bad*, huge amount of cruel rust visible; sprayed it every 5 mins, 3 times (WD40). Then started tightening the nut (went pretty well) which resulted a full turn (360degrees) then it stopped. I went backwards a quarter of a full turn (70-90degrees) in order to start over the tightening procedure from that point again... Sprayed again, started tightening... and here I expected the nut to go another full turn (which sounds a lot, I know, but half of the threaded parts of it was still out) BUT instead of that it went just a little, less then that quarter turn I already had before ... and THEN suddenly the whole thing shot itself out of the tube so the nut got completely free/loose, strut insert `bang`... went UP, the lifted wheel DOWN all the way, wow I should have it on camera including my face expression there. I would never think that this would happen. (loose nut+rust=fail) Luckily it did not when I got the whole assembly out a few days ago.... Now my susp is crippled until I get parts... What caused this, idk, but now I might have a strut housing that probably has no inner thread whatsoever (???)(inspection tomorrow) OR if get lucky again, it will take a new insert with a new gland nut securely. I have to get the whole thing out again (but this time I am not sure whether or not it should be done using the spring compressor while the shock is still in the car.)
Well, every day is a new day in Volvo-life... a new issue and some adrenalin + nighttime parts-hunting...

Hydraulic fluid isn't really compressible. I bet there is some in the bottom of that tube.
The nuts usually sit a couple threads above flush.
They clamp the top of the cartridge by the bottom of the nut, and there has to be thread enough for them to for sure reach.

I bet the cartridge is as fine as it was before. Seemed good when I drove it